FINAL CAUSES. 35 



the medium of human views; and our judgment of his bene- 

 volence can be formed only by reference to our own affec- 

 tions, and by their accordance with those ardent aspirations 

 after good, which the Author of our being has deeplyinter- 

 woven with our frame. 



The evidence of design and contrivance in the works of 

 nature carries with it the greatest force whenever we can 

 trace a coincidence between them and the products of hu- 

 man art. If in any unknown region of the earth we chanced 

 to discover a piece of machinery, of which the purpose was 

 manifest, we should not fail to ascribe it to the workman- 

 ship of some mechanist, possessed of intelligence, actuated 

 ,by a motive, and guided by intention. Farther, if we had 

 a previous experience of the operation of similar kinds of 

 mechanism, we could not doubt that the effect we saw pro- 

 duced was the one intended by the artificer. Thus, if in 

 an unexplored country, we saw^, moving upon the waters of 

 a lake, the trunk of a tree, carved into the shape of a boat, 

 we should immediately conclude that this form had been 

 given to it for the purpose of enabling it to float. If we 

 found it also provided with paddles at its sides, we should 

 infer, from our previous knowledge of the eff'ects of such in- 

 struments, that they were intended to give motion to this 

 boat, and we should not hesitate to conclude that the whole 

 was the work of human hands, and the product of human 

 intelligence and design. If, in addition, we found this boat 

 furnished with a rudder and with sails, we should at once 

 understand the object of these contrivances, and our ideas 

 of the skill of the artificer would rise in proportion to the 

 excellence of the apparatus, and the ingenuity displayed in 

 its adaptation to circumstances. 



Let us suppose that in another part of this lake we found 

 an insect,* shaped like the boat, and moving through the 

 water by successive impulses given to that medium by the 

 action of levers, extending from its sides, and shaped like 

 paddles, having the same kind of movement, and producing 



* Such as the Notoneda glanco, Lin., or water boatman, and the Dytiscus 

 marginalis, or water beetle. 



